1. Technical Field
This invention relates to a slag retaining device for use in tapping converters or hot metal ladles during the tapping of steel therefrom. The use of the device permits the tapping of steel free from slag.
2. Description of the Prior Art
Prior devices for blocking or minimizing slag carry over when tapping molten steel from a converter or ladle are known in the art and a typical disclosure of a device requiring manual placement is seen in Canadian Pat. No. 822,607. An example of a prior art floatable device may be seen in U.S. Pat. No. 4,462,574, W. M. Keenan, and U.S. Pat. No. 4,494,734, M. D. LaBate,
It is an object of the present invention to overcome the disadvantages of the above-mentioned prior art and to provide an improved automatically placed floatable device for minimizing slag carry over during tapping of molten metal from a converter or ladle and to provide a manually insertable device forming a closure having guide means and movable into the tap hole of the converter or ladle at a desired time to prevent molten slag from flowing therethrough. The device in its preferred form is combined with a cylindrical refractory sleeve positioned in the tap hole of the converter or ladle and forms circular valve seat for engagement with the slag retaining device and avoids the erosion of the material heretofore used in defining the tap hole which frequently resulted in an irregularly shaped tap hole and inability of a slag retaining device to properly seat therein.